1. Field of the Invention
The present invention relates to radar interferometry apparatus and to applications thereof.
2. Background of the Invention
Over the last few years, radar imaging has been enriched by the spectacular possibilities made available by combining a plurality of radar images coherently, as illustrated in particular by the following publications:
R. Golstein and H. Zebker "Interferometric radar measurement of ocean surface currents", Nature, 328, 707-709, 1987; PA1 C. Prati and F. Rocca "Improving slant-range resolution with multiple SAR surveys", IEEE Trans. Aerospace Elec. Sys., 29, 135-143, 1993; PA1 H. Zebker and R. Golstein "Topographic mapping from interferometric SAR observation", J. Geophys. Res., 91, 4993-5001, 1986; and PA1 D. Massonnet and T. Rabaute "Radar interferometry: limits and potential", IEEE Trans. Geosc. and Remote Sensing, 31, 455-464, 1993. PA1 the major axes thereof have the same length so that the satellites are accurately synchronous; PA1 the focuses are separated by a distance which is the same for each of the orbits of the receiver satellites and which is greater than the distance between the focuses of the orbit of the emitter satellite, such that the eccentricity of a receiver satellite orbit is different from that of the emitter satellite orbit; and PA1 the arguments of their perigees have values that are uniformly distributed over 360.degree. such that during one orbital period the receiver satellites travel round an ellipse over which they are uniformly distributed, said ellipse being centered on the position that the emitter satellite would have had if its orbit had the same ascending node longitude and the same phasing as the orbits of the receiver satellites.